1. Field
Example embodiments relate to a coating apparatus, a coating method thereof, and a method of forming an organic layer using the same that are capable of providing a layer with a substantially uniform thickness.
2. Description of the Related Art
As information communication industries have been rapidly developed, applications of display devices are also widely increased. Recently, display devices that can satisfy low power consumption, light weight, thin thickness, and high resolution are needed, e.g., flat panel display devices.
For example, a flat panel display device, e.g., a liquid crystal display (LCD) device and an organic light emitting diode (OLED) display device, may include an emission region and a thin film transistor (TFT) formed between opposite two substrates. In order to protect the emission region from external moisture, oxygen, etc., a sealing material may be applied to a periphery of the emission region to adhere the two substrates, encapsulating the emission region.
The flat panel display device may have a multi-layer structure, in which various layers, e.g., an organic layer, an inorganic layer, and a metal layer, may be deposited to form the emission region and the TFT. For example, an active matrix organic light emitting diode (AMOLED) display device may include a structure in which a buffer layer, a semiconductor layer, a gate insulating layer, a gate electrode, an interlayer insulating layer, source/drain electrodes, a protection layer, a planarization layer, a pixel defining layer, a lower electrode, an organic emission layer including an organic layer, an upper electrode, etc., are deposited. Further, the organic emission layer may include a hole injection layer and a hole transport layer between the lower electrode and the organic layer, and may further include an electron injection layer and an electron transport layer between the upper electrode and the organic layer.
The various layers in the flat panel display may be formed by applying a liquid coating material among the deposited layers, e.g., the organic layer, the interlayer insulating layer, the hole injection layer, etc. The liquid coating material may be dried to finalize a layer.